code: def df_daily():
      df = pd.DataFrame(
          {
              "ts": pd.date_range("2020-01-01", freq="D", periods=1000),
              "y": list(range(1000)),
          }
      )
      return df
  
imports: import pandas
  import pytest
  from testfixtures import LogCapture
  from greykite.common.aggregation_function_enum import AggregationFunctionEnum
  from greykite.common.constants import LOGGER_NAME
  from greykite.common.constants import PREDICTED_COL
  from greykite.framework.templates.autogen.forecast_config import EvaluationPeriodParam
  from greykite.framework.templates.autogen.forecast_config import ForecastConfig
  from greykite.framework.templates.autogen.forecast_config import MetadataParam
  from greykite.framework.templates.autogen.forecast_config import ModelComponentsParam
  from greykite.framework.templates.forecaster import Forecaster
  from greykite.framework.templates.lag_based_template import LagBasedTemplate
  from greykite.framework.templates.model_templates import ModelTemplateEnum
  from greykite.framework.utils.result_summary import summarize_grid_search_results
  from greykite.sklearn.estimator.lag_based_estimator import LagBasedEstimator
  from greykite.sklearn.estimator.lag_based_estimator import LagUnitEnum
label_desc: Use image node_id 1 for calling a global function with example usage: df_daily() and returns: df